doc: spelling error changes

Fixed multiple spelling errors.

Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Carlos E. Garcia <carlos@cgarcia.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/Documentation/dma-buf-sharing.txt b/Documentation/dma-buf-sharing.txt
index 7d61cef..67a4087 100644
--- a/Documentation/dma-buf-sharing.txt
+++ b/Documentation/dma-buf-sharing.txt
@@ -217,7 +217,7 @@
     and then allow further {map,unmap}_dma_buf operations from any buffer-user
     from the migrated backing-storage.
 
-   If the exporter cannot fulfil the backing-storage constraints of the new
+   If the exporter cannot fulfill the backing-storage constraints of the new
    buffer-user device as requested, dma_buf_attach() would return an error to
    denote non-compatibility of the new buffer-sharing request with the current
    buffer.